MEMS for Thermogravimetry: Fully Integrated Device for Inspection of Nanomasses

This paper presents a microelectromechanical-systems device for thermogravimetric analysis (TGA) with integrated thermal actuators. It consists of a sensing cantilever paddle connected to two separated thermal actuators, one at each side of the cantilever. An integrated thermocouple allows to measure directly the temperature difference between the heater at the tip of the cantilever paddle and the device silicon frame. The cantilever paddle vibration amplitude (frequency) is measured with an integrated piezoresistor. The temperature dependence of the resonance frequency on local heating with the integrated heater is investigated. Mass and temperature calibrations are performed from 0 to 6 ng and from 300 K to 823 K, respectively. To demonstrate the device performance, TGA of polyamide 6 and paraffin samples is carried out. TGA can be performed with the presented device in the temperature range from 298 K up to 920 K for sample masses as small as 0.8 ng. The mass sensitivity is about 164 Hz/ng at ambient temperature.